Grandpa Dave's Tightrope is the fifteenth episode of the third season of RS Mr. Conductor the Conductor and Friends, and the sixty-seventh episode overall. It is a parody of the Thomas and Friends episode, Toby's Tightrope.
- Bart (from The Simpsons) as Percy
- Grandpa Dave (from Arthur) as Toby
- Meg (from Family Guy) as Mavis
- Mayor Adam West (from Family Guy) as Sir Topham Hatt
- Goombas (from Mario) as The Troublesome Trucks
- Everyone else as Themselves
Narrator: "One day, Bart arrived at the quarry to collect some stone for his goombas. Snow and frost lay everywhere. There was not a sound to be heard.
Bart ventured further. He found Meg, the new teenage girl, resting in the shelter of some rocks."
Bart: "Cheer up, Meg."
Narrator: "He whistled. Meg was still remembering the trouble she'd had with goombas."
Meg: "Manager says I don't listen to advice. He says I've no business jauntering down Grandpa Dave's path. Grandpa Dave's a fusspot!"
Bart: "Grandpa Dave has forgotten more about goombas than you will ever know."
Narrator: "Replied Bart."
Bart: "You must put the goombas where he wants them, then you'll be a Really Useful Teenage Girl. Now if you'll excuse me, I have to take these goombas to the harbor."
Narrator: "Meg liked Bart, but she still wouldn't listen to his advice."
Meg: "Why shouldn't go on Grandpa Dave's path?"
Narrator: "The siding arrangements were awkward. To put the goombas where Grandpa Dave wanted them, Meg had to make several journeys.
She started making a plan."
Meg: "If we used the teeniest bit of Grandpa Dave's path."
Narrator: "She said to her driver."
Meg: "We would save all this bother."
Narrator: "Her driver, suspecting nothing, allowed them to go as far as the first level crossing.
A few days later, the weather changed. As the snow melted, the quarry grew busy again. Some lines were so long that Meg had to go beyond the level crossing. Now for her plan. She would go down further down the path with it seeming her fault."
Meg: "Can you keep a secret?"
Narrator: "She asked the goombas."
Goombas: "Yes, yes, yes."
Narrator: "They chattered."
Meg: "Will you bump me at the level crossing and tell no one I asked you?"
Narrator: "The goombas promised.
But while Meg was away, Grandpa Dave arrived. He decided to arrange the goombas himself. The goombas decided to bump him anyway.
They reached the level crossing and Grandpa Dave stopped. This was the signal for the goombas."
Goombas: "On, on, on!"
Narrator: "They yelled.
Grandpa Dave was away, with the goombas screaming and yelling behind him.
No one realized that melted snow had turned a stream ahead into a torrent and the bridge above it was about to collapse.
The road was now like a tightrope across the thundering water."
Grandpa Dave: "Stop, stop!"
Narrator: "Cried Grandpa Dave.
His driver fought for control. They came nearer and nearer to the bridge. The driver braked hard.
Grandpa Dave stopped, still on the path, but with his feet treading the tightrope over the abyss.
Meg was horrified, and quickly came to the rescue. Workmen anchored Grandpa Dave with chains while she pulled the goombas away. Then she helped Grandpa Dave to safety."
Meg: "I'm sorry about the goombas."
Narrator: "Said Meg."
Meg: "I can't think how you managed to stop them in time."
Grandpa Dave: "Oh well."
Narrator: "Said Grandpa Dave."
Grandpa Dave: "My driver told me about circus people who walk tightropes, but I just didn't fancy doing it myself."
Narrator: "Later, Mayor Adam West arrived."
Mayor Adam West: "A very smart piece of work."
Narrator: "He said."
Mayor Adam West: "Meg, you did well too, I hear."
Meg: "It was my fault about those goombas, sir."
Narrator: "She faulted."
Meg: "But if I could,"
Mayor Adam West: "Could what?"
Meg: "Come down the path sometimes, sir. Grandpa Dave says he'll show me what to do."
Mayor Adam West: "Certainly."
Narrator: "Replied Mayor West."
Mayor Adam West: "If your manager agrees."
Narrator: "And so it was arranged. Now Meg is as happy as can be, and Mayor West thinks she's Really Useful indeed."